Recent advances in heartworm disease.

This compilation of articles consists of four papers presented at the 19th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP) (held in New Orleans, LA, USA, on 10­14 August 2003) in a symposium session titled " Recent Advances in Heartworm Disease," organized and chaired by JohnW. McCall and Jorge Guerrero. The first paper(Guerrero) covered the American Heartworm Society's most recent revision of their guidelines for the diagnosis, prevention, and management of heartworm infection in dogs, based on new research and clinical experience, particularly in the areas of heartworm chemoprophylaxis, adulticide therapy,and serologic testing and retesting. The entire updated 2003 "Guidelines" are presented herein.One paper (McCall) reviewed the "soft-kill" adulticidal and "safety-net" (reach-back, retroactive,clinical prophylactic) activity of prolonged dosing of prophylactic doses of macrocyclic lactones,concluding that ivermectin is the most effective in this way, milbemycin oxime is the least effective,and the activity of injectable moxidectin and selamectin lies between that of ivermectin and milbemycin oxime. The two remaining papers provided an overview of the discovery, rediscovery,phylogeny, and biological association between Wolbachia endosymbionts and filarial nematodes(Genchi and co-authors) and compelling evidence that Wolbachia may play a major role in the immunopathogenesis of filarial diseases of man and animals (Kramer and co-authors).